Electrical system



Patented A ug. 23, 1927.

UNITED. STATES PATENT OFFICE.

WILLIAM B. cnuncn n, E CLEVELAND HEIGHTS, 01110, ASSIGNOR ro THE WHITE MOTOR coMrAnY, or CLEVELAND, 01110, A CORPORATION or 01110.

ELECTRICAL SYSTEM.

I A lication fled August 2', 192-5. Serial No. 51,283.

My invention relates to electrical systems and relates particularly to electrical systems, employing an electrical generator of the shunt field type, for'the purpose of supplying electrical current to one or more electro-responsive devices, such as electrical lamps or the like.

An object of my invention isto accomplish in a system, comprising a shunt wound electrical generator and one or more current consuming devices such as electrical lamps adapted to be operated by current from the generator, the substantial discontinuance of the generation of electrical current without causing an impulse of relatively high voltage current to pass through one or more of the lamps thereby burning out the lamp or decreasing its efiectual life. I

Another object of my invention is to accomplish in a system of the above type, the disconnection of one or more of the electroresponsive devices from the energizing circuit comprising thegenerator, without causing aninjurious momentary flow of current through other of the electro-responsive devices which are desired to be continued in the electrical circuit of the generator.

.Another object of my invention is to ac- ',complish in an electrical system comprising a shunt wopnd electrical generator and a plurality of electro-responsive devices such as lamps, the switching on and ofi oi the lamps 1n an efiicient manner; andwithout injury to the lamps, or the generator;

35 Another object of m invention is to accomplish-in a system 0 the above type comprising a voltage regulator, the disabling of the generator to effect discontinuance of electrical current flow to the load from the generator and at the same time to disable the minvention is to ac-' ing to entirely remove the load from switching to entirely remove the load from the generator at the same time todisable the voltage regulator so that it will discontinue vibrating. 7

Other objects of my invention and the.

invention itself will be apparent'from the following description of an embodiment of my invention and in which description reference will be had to the accompanying drawing forming a part of this specification In the drawing the single figure shows an electrical system diagrammatically illustrating an embodiment of my invention.

Referring to the drawing, at 2 I show a rotatable armature of an electrical genera tor, electrical cont-act with which is bad by means of brushes 3 and which 'generatrir com rises an ener izin field windin 4 confar as described, the generator and other,

associated parts are as commonly provided for the purpose of supplying current for the purpose of lighting lamps, for such a purpose as illuminatin an automative truck or other automative ve 1icle upon which the generator may be installed.

The generator having the armature 2 may be of any of the usual types and may have a low speed characteristic involving a high armature reaction. Such a generator, for instance, as will be capable of supplying current for illuminating purposes at seven volts when it's armature tube is rotated at a speed of,-say, 400 revolutions per minute, ma be used.

ii the embodiment of my inventlon illustrated I have shown a lamp load for the generator comprising motor vehicle headlights illustrated at 9 and 10, a rear tall lamp 11, a dashlamp 12 and a spotlight 13.

The headlights and spotlights will be of relatively high current consumingcapacity, being preferably of a high candle power such as 21 candle power each, whereas the rear tail and dash lamps shown at 11 and may be rated at 6 to .8 volts whereas the serially connected lamps, 11 and 12, would in such case be rated, preferably, at from 3 to 4. volts each. The headlights are multiply connected across the circuit conductor 14 and ground. 15 and which ground may be of the contacts 18 and 19 and the width of a return conductor to the generator and con nected to the generator armature brush- 3. or it may comprise in part'rthe metallic trams of the motor vehicle. show, at 16, an electrical switch comprising a blade 17 and stationary contacts 18 and 19. The spacing the contact end 20 of thelblade are such that the said contact end is slifliciently wide. that it may span the contactsv 18 and 19, that is,'

it will overlap andm'ake contact with both of the said contactsat the same. time when placed in a position'between the contacts.

This arrangement insures, for a purpose later to be related, that when moving the blade 17 from a position wherein it makes contact with the contact 18 to a position wherein such contact is broken and contact had with the. contact point 19,'that contact will be had with the contact point 19 before contact with 18 is broken; that is, the

make-before-break type.

Similarly, a switch v21,'is provided having switch-will be of what is known as the I a switch blade 22 whose contacten'd 23 is of sufiicient width relativmto the spacing of the contacts 24 and 25, that prior to leaving the contact 24, vcontactjvvill .be .had'by the blade contact end with tits contact '25,

A resistance coil 26 is connected between the contact points 27 and 24 of the switch 21 and with the switch blade 22 making contact with contact 24, will be serially included in the energizing circuit of the multipled headlights 9 and 10. J

Thehead lamps 9 and .10 are adapted to be illuminated whenever the generator is operated at a sufficient speed, and the switch blade 22 is making contact with the contact point 27 of the switch. whereby full current ,cOnnected lamps 9 and 10. At the same la'mp 12 will also be lighted, in the first time, the headlights are lighted, the rear tail lamps 11 and the serially connected dashcase through the resistance coil 26, and in the latter case above mentioned, directly through switch blade 22 and contact point 24-, The above lighting of lamps 9 to 12 inclusive will only occur, however if the switch blade 17 of the switch 16 is in some other position than that wherein contact is had with the switch contact point 19. In the latter case the generator will be short circuited, and. the lamps 9 to 12 inclusive shunted, and little or no current generated and no current will pass from the generator through the lamps.

At any time, whenever switch blades 17 or 22 make connection to ground by contacting with switch points 19 or 25, respectively,

the generator will be short circuited and will generate little or no current.

The short circuiting of a shunt wound generator, such as that employed in the system described herein, will always short circuit the shunt field coil 4 so that no energizing current can pass through such field coil to energize the field of the generator. If the generator field is not energized the rotation of the armature 2 will not accomplish the cutting of lines of force which otherwise would be set up by the energized field, but which, in the present case would not be set At 5 I show the energizing winding of the voltage regulator which is also multiply connected across the generator brushes 3 and which will also be short circuited whenever the switch blades 17 or 22 make contact with the switch points 19 or 25, respectively, to short circuit the generator. In all prior systems, so far as I am aware, it has been customary to open the circuit leading from the generator to the load in order to discontinue supplying current to the-load, this being done, commonly, by opening the circuit of the circuit conductor 28 as at 30. In such systems the voltage regulator will continue to function and will vibrate its armature at a very rapid rate causing nnduewear at its contacts 7.

In the system of my invention herein illustrated whenever the switch cont-acts mentioned. are closed, thewinding 5 of the voltage regulator magnet is alsoshort circuited preventing current from passing through the same. At the same time the generator field 4 being shunted, the generator will not generate any considerable amount of current, generating only perhaps a very small amount of current due to residual magnetism contained in the iron cores of the magnets. The generation of this small amount of current is negligible in its efi'ects on the system herein described.

In the systems of theprior art mentioned 7 .disconnection of another part of the load,

by arranging the switch contacts and providing a switch blade to cooperate there with in the case of both the swltehes 16 and 21 whereby whenever the circuit of a part ofthe load is opened that prior to the 0 ening of such circuit, the movable switch b ade will make contact with a grounded contact of the switch and short circuit the generator. Thus, assuming that "the switch blade 17 were making contact with the point 18 of the switch 16, and the switch blade 22 were making contact with the point 24 of the switch 21, and it is desired to eliminate the spotlight from the circuit to extinguish it, then the movement of the blade 17 toward the position illustrated wherein it does not make contact with any switch point is attended, first, by its making contact with the grounded contact 19 toshort circuit the generator and its load, just prior to its reaching open circuit position. Thus no inductive discharge through the headlights 9 and 10 can occur since at the moment of breaking of the contact point 18 in the circuit of the spotlight, the generator and the said headlights will be short-circuited through contact point 19. Upon the switch blade 17 leaving the point 19 for its open circuit. position, the generator will be reenergized and will come up to normal voltage, but without even momentarily producing a current of excessive voltage. If, for any reason, it 1s desired to dlscontinue the energization of the lamps 9 to- 12 inclusive,

this can be done in like manner by moving the switch blade 22 from its bright osition in contact with the switch point 2 of switch 21 or from its dim position in contact with switch point 24 thereof to the grounded switch point 25 with whichit will make contact just prior to the time it leaves contact with the switch point 24.

Since it is unlikely that it will be desired to operate the spotlight 13 exclusively, in

the embodiment of my invention illustrated,

I have shown no open circuit position for i the switch 21 asillustrated for the switch 16 though, of course, one could be provided. With no lights lighted, the'switch 21 will have its blade 22 take the short circuiting position and in this position the generator will be short circuited and will produce no considerable current.

The system of my invention is applicable to many dltfereut uses, but in theembodiment illustrated I have shown it' as applied to the electrical system of a motor vehicle employing no storage battery in the lighting circuit. With such motor vehicles as trucks and the like, it is highly desirableto eliminate the necessity for a storage battery since the up-keep of a storage battery in such a vehicle is very costly and the servicing of such a storage battery is diflicult. Moreover, the investment required will be unduly large since the percentage of the time lighting current is required, is but a small part of the total travelling time. When in use, the trucks are usually in motion and their engines are operating, so that parking lighting service is not generally requlred, and small kerosene lamps or the like, are commonly used at such rare times when the truck is at a standstill for a con siderable period of time.

Having thus described my invention in a specific embodiment, I am aware that numerous and extensive departures may be made from the embodiment herein illustrated and described, but without departing from the spirit of my invention.

I claim v 1. In an electrical system comprising a shunt wound generator, a load therefor, a switch having a set of make-before-break contacts having the make contacts there-of connected directly across the generator output terminals, and the break contacts in the circuit of said generator and load.

2. In an electrical system, a shunt wound generator, a load therefor, a switch, and

means associated with said switch adapted in a continuous movement to successively shorteircuit the generator, open the load circuit and remove the shorteircuit from th generator.

3. In' an electrical system, a shunt wound generator, a load therefor divided into a plurality ofparts, a first part thereof comprising an electrical lamp filament, a switch for controlling the circuit of a second part of said load, and means associated with said switch adapted in a continuous movement to successively shorteircuit the generator, open the load circuit and-remove the shorteircuit from the generator.

4. In an electrical system, a shunt wound generator, a load therefor, a voltage regulator energized from the generator and adapted to be de-energized when the generator is 5. In an electrical systein, a, shunt wound cuited, and means associated with said generator, a load therefor divided into. a switch adapted in a continuous movement to 10 plurality of parts, a first part thereof comsuccessively shortcircuit the generator, open prising an electrical lamp filament,- a switch the load clrcuit and remove the shortcircuit for controlling the circuit of a second part from the generator. of said load, a voltage regulator energized Intestimony whereof I hereunto aflix my from the generator and adapted to be designature this 18th da of August, 1925. energized when the generator is short-cir- WILLIAKI B. CHURCHER. 

